Hydraulic mechanism



FIG. 1 is a perspective view. The top and bottom of the hydraulic mechanism are unornamented.

FIG. 2 is a front view.

FIG. 3 is a left side view.

FIG. 4 is a right side view; and,

FIG. 5 is a rear view thereof. 

The ornamental design for a hydraulic mechanism, as shown and described. 